Buy a dedicated Windows box to run the sim on. The built-in graphics for PCs is pretty good now. Go to a custom shop and tell them what you want. I've been a customer of a shop down the way for twenty years, they sell PCs as low as $250.

http://www.infotechnow.com/index.php?cPath=55

Or buy a used, (slightly) older machine and re-install Windows (or Linix) on an SSD. The solid-state drive is a game changer.

Most of the simulators are pretty old, and probably won't tax a modern PC.

Ron Wanttaja